Volute brake mechanism



Oct. 20, 1931. s, BARROWS 1,828,218

VOLUTE BRAKE MECHANISM Filed June 3. 1927 Patented Oct. 20, 1931 DONALDs. BABROWS, or nocnns'rnn, NEW" rnninor NEW YORK, N. Y., A

YORK, ASSIGNOR TO THE SYMINGTON COM- con-rcnnrion or MARYLAND VOLUTEBRAKE MECHANISM Application filed June 3,

The invention relates to brake mechanism for rallway cars. 7

The principal object of the invention, gensystem.

It is well known that in. the ordinary type of hand brake in which thereis provided a drum or the like about and onto which the chain or otherflexible member of the brake mechanism is wound, the winding rate may beand usually is the same at all stages during the application of thebrakes, a condition which doesnot result in the most efficientoperation. Accordingly, I have designed the present invention which hasfor an important object the provision of a brake chain windingmechanismof such construction that the rate at which the chain or other flexiblemember is wound in decreases as the slack is taken up and the tensionincreased, there being consequently a greater leverage as greaterresistance is met. 7

An important object is to provide a novel bracket structure or mountingfor thedrum and associated parts, the mounting including detachablebearing means facilitating as sembly.

Another object of the invention is to provide a brake mechanism of thischaracter which is free from the disadvantages inher-' ent to the use ofworm gearing often provided as a means for obtaining a high lever a e iv I Inasmuch as the shafts and chains for brake mechanism must be ofsubstantial dimensions to possess the requisite strength and as it isimpractical'to employ large winding Wheels, the amount of pull that canbe produced by hand power is rather limited except by providing anelaborate reducing gear mechanism of such complexity and Weight, as wellas size, as to preclude its successful employment. f As it thereforebecomes necessary to keep the size of the parts i within reasonablelimits while providing means for multiplyingthe applied power, I

1927. Serial No. 196,347.

have conceived the present invention which has for a still more specificobject the provision of a volute drum which is, manually rotated forwinding the brake setting chain, the drum, shaft or staff and the othercombined and associated parts of the mechanism being all of such natureas to be simple and inexpensive to manufacture, easy to install in oldor new equipment, positive in action, efii- 'cient and durable inservice, and a general improvement in the art.

To the attainment of'the foregoing and other objects and advantages, theinvention preferably consists in the details of construction and thearrangement and combination of parts to be hereinafter more fully de-.scribed and claimed, and illustrated in the accompanying drawingsinwhich:

Figure 1 is a side elevation of the device.

Figure 2 is a top plan view thereof with the operating shaft removedfrom its socket.

Figure 3 is a horizontal cross section taken on the line 33 of Figure 1and illustrating one means for rotatably mounting the lower end of thevolute drum. 8

Figure 4 is a fragmentary side elevation illustrating a modified meansfor maintaining the lower end of the drum in journaled position.

Figure 5 is a detail horizontal section taken on the line 5-5 of Figurel.

Referring more particularly to the drawings, I have shown the mountingfor the brake operating mechanism as comprising an angular bracketindicated generally by the numeral 1, this .bracketbeing capableofformation as a single casting though there are naturally no limitationsin this particular inasmuch as it could be constructed of severaldifferent parts secured together in any preferred manner. Describing thebracket in detail, it may be said to include a main or upright portion 2which terminates. at its upper and lower ends in substantiallyhorizontal arm portions 3 and 4:, respectively, the former of whichserves as a base forattachment to a car or the like and is formed with abearing sleeve 5 and the latter of which may be of substantiallyU-shaped yoke form including arms 6. The bracket 1 is intended toconstitute the sole support or mounting for the winding member to bedescribed and the upper arm 3 is therefore represented as formed betweenthe upright por- 5 tion 2 and the bearing sleeve 5 with a hearing 7which may actually consist sim ly of an opening 8 surrounded by an enarged s. As a matter of fact, details such as together with otherdetails such as the 10 provision of reinforcing webs or ribs at theoints of greatest strain, may be varied withm wide limits. The lower arm4 carries a bearing structure, to be described, alining with the bearing7.

,The winding drum is indicated generally at 9 and is here shown as ofvolute form or vided with a volute web or rib 10, though 3 t Shduid beunderstood that one of a differbnt variety ma be used. At one end thisdrum has a re uced extension 11 constituting a trunnion journaled withinthe opening "8 m the bearing 7, this end being formed at "the base ofsaid extension with a flange 12 constituting a stop or abutment uponwhich is seated the flanged end 13 of a gear 14. The

other end of the drum is formed with an inverted frusto-conical ortapered bearing portion 15 which mer s into a reduced extension 16 andboth 0 which constitute a trunfiii) the tapered portion and extensionbeing ournaled within a corresponding opening in a block-like bearing 17located within the confines of the yoke including the arms 6, thisbearing member 17 being retained in position as for instance by means ofa rivet 18 or the like passing through it and the arms 6. An alternativemounting for the lower end of the drum will be described hereinafterthough this is a form which will give entire:

=' satisfaction.

The drum 9 is adapted to have the brake setting chain, not shown,secured thereto and wra ped thereabout, the point of connection of t echain bein preferably at the lower end of the drum or which reason thelower end is shown as having a slot 19 therein for receiving the endmostlink of the chain or a ring carried by the chain. lVhile it is true thatany suita le means might be )rovided 56 for actually securing the chainto t e drum,

the'holding means is here represented as including a pin 20 traversingthe slot and held against displacement as by means of a cotter 21. Thislower end of the drum to which the #5 chain is secured is of the largestdiameter inasmuch as comparatively small leverage is needed at firstwhen winding in the chain, the initial or preliminary movement beingprin- V oipally to take up slack. The drum may con- 'veifi'entlydecrease in effective radius from the lower end to the upper and theremay even be a substantially zero effective radius at or near the upperend if such is found advisable.

The operating means for imparting rotary movement to the drum preferablycomprises a rotatable member22j ournaled within the hearing sleeve 5 andhaving its lower end formed with teeth 23 meshing with the gear 14.Immediately above the bearing sleeve 5 the member 22 may have anoutstanding flange 24 for the purpose of preventing it from longitudinaldisplacement, and the upper end of the member 23 is or may be formedwith a socket 25 within which is removably engaged the ta ered lower endof the manually operable brake staff 26 equipped with the usual handwheel or the like, not shown. To provide a driving connection bet-weenthe member 22 and the shaft 26, it is preferable that the socket andtapered end of the staff be noncircular or angular in cross section asillustrated in Figure 2 though it is of course conceivable that adifferent arrangement might be provided if desired. The staff may be secured to the operating member 22 by inserting a pin, not shown withinsuitable holes 27 in the member 22 and tapered end of the staff. Theseand other minor variations may readily suggest themselves depending uponcir cumstances that may arise or conditions to be met. To hold themember 22 in the proper operative relation to the bearing sleeve 5 andgear 14, I have found it convenient to provide a transverse element suchas the rivet 28 passing through the sleeve 5 and intersecting aperipheral groove 29 in the member 22. Clearly, this member 28 cannotinterfere with rotation of the member 22, its sole function being toprevent longitudinal movement of the latter with respect to its bearingsleeve 5.

Instead of providing the bearin block 17 above described, I may make use0 the alternative mounting for the lower end of the drum as illustratedin Figures 4 and 5. Referring to these views in detail, I have-shown thebracket member as having its lower end formed with an arm 30 terminatingin a split sleeve 31 which has its free edges ink tially extendedoutwardly as shown by dotted lines in Figure 5. The lower end of thedrum is of exactly the same form as above described and is journaledwithin a block-like bearing member 32 formed with a reduced .'-1::'

portion 33 received within the sp'l'it sleeve 31, this reduced portionhaving recesses or cut-awayfiportion's 34 at op osite sides of itscenterde ning an outstan ing rib 35.

In assembling the form of the invention embodying the modified lowerbearing for the lowerend'of the drum, the bearing member 32 is insertedwithin the s lit sleeve 81 and the outwardly extending ree edges of thesleeve, which edges are represented at'86, 351

are then bent inwardly toward 'each other so as to'engage within therecesses or cut-away portions 34 in the bearing member, the rib 35 beinglocated between. the confronting edges'of these bent portions.

In operation, it will be apparent that when the staff 26 is turned, asby means of the usual hand wheel, the teeth 23 on the rotary member 22will operate to drive the gear 14 and effect rotation of the drum 9. Thechain, not shown, which is attached to the lower and larger end of thedrum will then of course be wound upon it within the successiveconvolutions. As the lower end is the larger, the initial movement ofthe chain will e considerable so that the slack will be quickly takenup. As the chain leaves the lowermost convolution and is wound onto thenext, the rate of movement thereof is decreased but the leverage greatlyincreased so that b means of the expenditure of no more than t 1e usualamount of time, effort and labor the brake mechanism to be operated isapplied or set sufficiently and powerfully so as to insure the properbraking action. While it is not illustrated, it will be understood thatuse may be made of the usual or any suitable pawl and ratchet mechanismfor preventing prema: ture unwinding of the chain and release of thebrakes.

From the foregoing description and a study of the drawings it will beapparent that I have thus provided a brake operating mechanism which isnot only simple and inexpensive in construction and easy to install, butlight in weight and compact 1n form, there being an avoidance of anyexcessively heavy, large or cumbersome parts. It is believed that theconstruction, operation and adyantages will be readily apparent to oneskilled in the art without further explanation.

lVhile I have shown and described the preferred embodiment of theinvention, it should be understood that the disclosure is merely anexemplification of the principles involved as the right is reserved tomake all such changes in the details of construction as will widen thefield of utility and increase the adaptability of the device providedsuch changes constitute no departure from the spirit of the invention orthe scope of the claims hereunto appended.

Having thus described the invention, I claim:

1. In a brake operating mechanism, a support comprising a base aperturedto provide a bearing, a depending arm with a bifurcated end underlyingthe apertured portion of the base, a drum journaled at its upper endwithin the apertured portion of the base and provided with means forattachment of a flexible member thereto, the drum having a flange and aplurality of convolutions constituting a seat to receive the flexiblememher, and a bearing block embraced by and connected to the bifurcatedend ofthe support arm and serving to rotatably mount the lower end ofthe drum;

2. In a brake operating mechanism, a support, a drum journaled at itsupper end within the support and provided with 'means for attachment ofa flexible member thereto, the drum having a flange and a plurality ofconvolutions constituting a seat to receive the flexible member, thatportion of the drum to which theflexible member is attached being thelarger and the successive convolutions being reduced in diameter, an armextending from said support and formed with an end underlying said andembracing the lower end thereof, and a bearing block for said lower endheld in the bifurcated end of the arm.

3. In a brake operating mechanism, a suport,. a drum journaled withinthe support at both ends and provided with means for attachmentof aflexible member thereto, the connection at one end of said drumcomprising a bearingblock separable from said support to facilitateassembly of the mech anism, the drum having a flange and a plurality ofconvolutions constituting a seat to receive the flexible member, amanually operable member, and gear connections between said manuallyoperable member and the drum.

i. In a brake operating mechanism, a supporting bracket having upper andlower bear ings therein, said lower bearing comprising a removablebearing bifurcated portion of the bracket, a drum having its endsjournaled within the bearings, said drum being adapted to have aflexible brake applying element secured thereto and having a continuousflange defining seat for the reception of the flexible element, and gearmeans for rotating the drum from a remote point.

5. In a brake operating mechanism, a supporting bracket and lower armbifurcated and detachably receiving a lower bearing, a drum havingextensions on its ends journaled within the bearings, the drum having aseat, means at one end of the seat for connecting a flexible brakesetting member thereto, a gear on the other end of the drum, and amanually operable gear member rotatable in the upper end of the bracketand meshing with said gear.

6. In a brake operating mechanism, a. sup port, spaced bearings in thesupport, a drum with a gear wheel thereon and having its ends formedwith extensions constituting trunnions journaled within said bearings,said drum having a seat means for connect ing to the drum a flexibleelement adapted to be wound onto the seat, and means for rotating thedrum comprising a rotatable member formed with teeth at one end meshingwith the gear wheel on the drum, the other end being rotatably receivedin a bearing sleeve on the support, and means intersecting said sleeveand engaging a peripheral groove in the rotatable member for retainmg itin place,

drum, bifurcated block embraced by a having an upper bearing 7. In a'brake operating mechanism, a support, spaced bearings in the support,one of ltid bearings comprising a block detachably received in abifurcated portion of the support, a drum having its ends formed withextensions constituting trunnions journaled within said bearings, saiddrum having a defining a seat, means for drum a flexible elementsupport.

8. In a brake operating mechanism, a support comprisin a base, an armdepending therefrom and ormed with a socket portion underl said base, abearing block received in saidsoc et, means intersecting said socket andblock for retaining the latter in position s rotatably mounted andpositively driven drum of volute form provided at one end with means forattachment of a flexible element thereto and formed with a continuousflange defining a seat for the flexible element, said drum terminatingat its ends in trunnions respectively mounted in the base and bearingblock of the support.

In testimony whereof I aflix my signature.

DONALD S. BARROVVS.

